The long-term goal of our project is to design, build, and market a next-generation optometer for comprehensive measurement of the eye's refractive state. Such an optometer will determine not only the routine refractive errors of defocus and astigmatism normally measured by clinical optometers, but will also determine the higher-order optical aberrations (e.g. coma, spherical aberration, etc.) which characterize abnormal or pathological eyes. In Phase-I of this project, our first aim will be to validate our design concept against accepted clinical standards. This will be done by comparing refractive errors measured on human eyes by our prototype system with results from commercial autorefractors and with subjective refractions determined by an experienced optometrist. Our second aim will be to extend our current measurement techniques to make them robust enough to enable routine measurement of pathological eyes and healthy eyes with abnormally large aberrations. This latter aim will be achieved by collecting, analyzing, and modeling sample data from a representative set of abnormal eyes. The results will provide a basis for discovering and implementing new data processing algorithms through improved understanding of the fundamental optical basis of pathological aberrations. PROPOSED COMMERCIAL APPLICATION This instrument will be useful in basic optometric practice, and in clinical research studies of the optical outcome of refractive surgery, inter-ocular lens implants, corneal pathology (e.g, keratoconus), tear film breakup, contact lens therapy (e.g. orthokeratology), early detection of cataract, or any other treatment or intervention which is expected to have an impact on the optical performance of the eye.